POSSIBILITY THE MIDLAND-ROSS AIR BRAKE APPLICATION VALVE ASSEMBLY INTERNALVALVE CAGE MAY DETERIORATE AND CRACK AND EVENTUALLY FAIL.IF A FAILURE OCCURS, THE VALVE PISTON COULD BE PUSHED OUT OF THE VALVE BODY, RESULTING IN A RAPID LOSS OF AIR AT THE APPLICATION VALVE CAUSING A LOSS OF BRAKE ACTION.(CORRECT BY REPLACING INTERNAL VALVE CAGE WITH ONE OF IMPROVED CONSTRUCTION AND MATERIAL.)